Chicago Cubs' Ben Zobrist, right, high-fives teammate Addison Russell after batting him in on a two-run home run in the second inning of an interleague baseball game against the Baltimore Orioles in Baltimore, Friday, July 14, 2017. (AP Photo/Patrick Semansky)

Chicago Cubs' Ben Zobrist, right, gestures after hitting a double in front of Baltimore Orioles second baseman Jonathan Schoop in the first inning of an interleague baseball game in Baltimore, Friday, July 14, 2017. (AP Photo/Patrick Semansky)

Chicago Cubs starting pitcher Mike Montgomery throws to the Baltimore Orioles in the second inning of an interleague baseball game in Baltimore, Friday, July 14, 2017. (AP Photo/Patrick Semansky)

Baltimore Orioles starting pitcher Kevin Gausman throws to the Chicago Cubs in the first inning of an interleague baseball game in Baltimore, Friday, July 14, 2017. (AP Photo/Patrick Semansky)

Baltimore Orioles starting pitcher Kevin Gausman walks off the field after the top of the second inning of an interleague baseball game against the Chicago Cubs in Baltimore, Friday, July 14, 2017. Gausman gave up two runs to Chicago in the second. (AP Photo/Patrick Semansky)

Willson Contreras and Kyle Schwarber hit back-to-back homers in a four-run first inning for Chicago. Ben Zobrist also homered onto the flag court behind the right field scoreboard and Jason Heyward reached Eutaw Street with another towering shot.

Chicago improved to 3-6 in interleague play after going 15-5 against the AL last season.

Welington Castillo's ninth home run was a solo shot in the third for Baltimore, which left 10 runners on base.

Contreras provided a 3-0 lead with a homer into the Cubs' bullpen. Schwarber hammered Kevin Gausman's next pitch to almost the exact spot.

Zobrist and Heyward hit two-run homers in the second and third, respectively, to boost the margin to 8-0. Gausman tied a career-high by allowing eight runs and seven hits over three innings. He also gave up four home runs — the most of his career.

Mark Trumbo, Trey Mancini and Joey Rickard had RBI singles in the fifth off reliever Justin Grimm to cut the lead to 8-6.

MOVES

Cubs: To make room for LHP Jose Quintana, who was acquired from the White Sox on Thursday, RHP Dylan Floro was optioned to Triple-A Iowa.

Orioles: OF Craig Gentry cleared waivers and was assigned to Triple-A Norfolk.

TRAINER'S ROOM

Orioles: 1B Chris Davis (strained right oblique) returned from the 10-day DL and went 1 for 5 with an RBI double in the fourth. . INF Ryan Flaherty (right shoulder inflammation) could begin a rehab assignment by the end of next week.

UP NEXT

Cubs: RHP Jake Arrieta (8-7, 4.35 ERA) will make his second career start against his former team. He previously beat the Orioles on Aug. 22, 2014, when he allowed one run over seven innings.

Orioles: LHP Wade Miley (4-7, 4.97 ERA) is looking to build off his previous start when he gave up one run and eight hits over 5 2/3 innings against the Twins. Miley is second in the AL with 51 walks.